Background Given the projected trends in population ageing and population growth, the number of people with dementia is expected to increase. In addition, strong evidence has emerged supporting the importance of potentially modifiable risk factors for dementia. Characterising the distribution and magnitude of anticipated growth is crucial for public health planning and resource prioritisation. This study aimed to improve on previous forecasts of dementia prevalence by producing country-level estimates and incorporating information on selected risk factors. MethodsWe forecasted the prevalence of dementia attributable to the three dementia risk factors included in the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 (high body-mass index, high fasting plasma glucose, and smoking) from 2019 to 2050, using relative risks and forecasted risk factor prevalence to predict GBD risk-attributable prevalence in 2050 globally and by world region and country. Using linear regression models with education included as an additional predictor, we then forecasted the prevalence of dementia not attributable to GBD risks. To assess the relative contribution of future trends in GBD risk factors, education, population growth, and population ageing, we did a decomposition analysis. FindingsWe estimated that the number of people with dementia would increase from 57•4 (95% uncertainty interval 50•4-65•1) million cases globally in 2019 to 152•8 (130•8-175•9) million cases in 2050. Despite large increases in the projected number of people living with dementia, age-standardised both-sex prevalence remained stable between 2019 and 2050 (global percentage change of 0•1% [-7•5 to 10•8]). We estimated that there were more women with dementia than men with dementia globally in 2019 (female-to-male ratio of 1•69 [1•64-1•73]), and we expect this pattern to continue to 2050 (female-to-male ratio of 1•67 [1•52-1•85]). There was geographical heterogeneity in the projected increases across countries and regions, with the smallest percentage changes in the number of projected dementia cases in high-income Asia Pacific (53% [41-67]) and western Europe (74% [58-90]), and the largest in north Africa and the Middle East (367% [329-403]) and eastern sub-Saharan Africa (357% [323-395]). Projected increases in cases could largely be attributed to population growth and population ageing, although their relative importance varied by world region, with population growth contributing most to the increases in sub-Saharan Africa and population ageing contributing most to the increases in east Asia. Interpretation Growth in the number of individuals living with dementia underscores the need for public health planning efforts and policy to address the needs of this group. Country-level estimates can be used to inform national planning efforts and decisions. Multifaceted approaches, including scaling up interventions to address modifiable risk factors and investing in research on biological mechanisms, will be key in addressing the expected incr...

The hypothesis that the S allele of the 5-HTTLPR serotonin transporter promoter region is associated with increased risk of depression, but only in individuals exposed to stressful situations, has generated much interest, research, and controversy since first proposed in 2003. Multiple meta-analyses combining results from heterogeneous analyses have not settled the issue. To determine the magnitude of the interaction and the conditions under which it might be observed, we performed new analyses on 31 datasets containing 38 802 European-ancestry subjects genotyped for 5-HTTLPR and assessed for depression and childhood maltreatment or other stressful life events, and meta-analyzed the results. Analyses targeted two stressors (narrow, broad) and two depression outcomes (current, lifetime). All groups that published on this topic prior to the initiation of our study and met the assessment and sample size criteria were invited to participate. Additional groups, identified by consortium members or self-identified in response to our protocol (published prior to the start of analysis1) with qualifying unpublished data were also invited to participate. A uniform data analysis script implementing the protocol was executed by each of the consortium members. Our findings do not support the interaction hypothesis. We found no subgroups or variable definitions for which an interaction between stress and 5-HTTLPR genotype was statistically significant. In contrast, our findings for the main effects of life stressors (strong risk factor) and 5-HTTLPR genotype (no impact on risk) are strikingly consistent across our contributing studies, the original study reporting the interaction, and subsequent meta-analyses. Our conclusion is that if an interaction exists in which the S allele of 5-HTTLPR increases risk of depression only in stressed individuals, then it is not broadly generalizable, but must be of modest effect size and only observable in limited situations.

Resilience comprises cognitive and behavioural tendencies that reflect dispositional character traits and patterns of behaviour that develop through life experience. Resilience is associated with positive mental and physical health outcomes although debate over its function as a predictor and/or outcome of successful stressful life conditions exists. Findings are confounded by a range of operational definitions. This study tested the factorial structure of the Connor and Davidson Resilience Scale (CD-RISC) and assessed its independence of two broad affective constructs, positive and negative affect. Participants (n = 1775) comprised the youngest adult cohort from the PATH study from Canberra, Australia. Results supported a uni-dimensional CD-RISC measure that was independent of affect at an item level, but supported strong associations between resilience and affect factors. Comparable Goodness of Fit Indices supported strict invariance between genders on an oblique 3-factor model of resilience and affect.

Ryff's (1989b) Psychological Well-Being (PWB) scales measure six related constructs of human functioning. The present paper examined the validity of Ryff's 6-factor PWB model, using data from a life events study (N = 401) and an organisational climate study (N = 679). Previous validation studies, using Confirmatory Factor Analysis (CFA), have identified alternative PWB models, but limitations include the use of shorter scale versions with items relating to a number of life domains within the same PWB factor, and failure to examine the influence of participants' socio-demographic characteristics on PWB. In this study, Exploratory Factor Analysis (EFA) mostly found consistency in the PWB items and structure between the two studies whereby a 3-factor model delineated between items relating to Autonomy, Positive Relations and a superordinate factor comprising the other PWB factors. Using CFA, Goodness of Fit indices reached acceptable levels for the adjusted PWB model identified by the EFA, whilst differences between adjusted models of PWB previously identified in the literature were hardly evident. Post-hoc analysis by gender demonstrated socio-demographic effects on the structure and items that comprise PWB. Further development of PWB measures is needed to reflect its hierarchical and multi-dimensional nature. In the scales' current form, the construct validation of the PWB factors will continue to be problematic and will fail to adequately evaluate the nature and impact of PWB.Decades of research have related notions of positive mental and physical health with the absence of such adverse states as depression, anxiety, and physical illness. However, a number of 2 researchers have proposed that well-being is not necessarily the antithesis to these constructs of ill-being (Kahneman, 1999;Ryff, 1989a). A major challenge is to identify relevant dimensions of well-being and to understand how these dimensions are shaped by various human experiences.Ryan and Deci (2001) have described two distinct, yet related approaches with which most psychological theories of well-being could be aligned. The Hedonic, or Subjective WellBeing (SWB) approach, focused on immediate human functioning and experience, and was associated with perceptions of pleasure, displeasure, satisfaction, and happiness. With philosophical roots in antiquity and more recently in Priestley and Bentham's 'greatest happiness principle', models of SWB have perhaps been the most frequently reported on within the wellbeing literature (Diener, Suh, Lucas, & Smith, 1999). Alternatively, a Eudaimonic or Psychological Well-Being (PWB) model emphasises those mechanisms that are associated with healthy human functioning and adjustment. Whilst daily SWB fluctuates with life experiences (Headey 2000, Heady & Wearing, 1989, PWB is a relatively stable construct that captures those aspects of human functioning more likely to lead to adaptive human functioning and positive experiences (Ryan & Deci, 2001). Such theories are not new. As with SWB, PWB is grounded in an...

Psychological well-being components are significant predictors of subjective well-being affect states that increase vulnerability to depression and anxiety.

BackgroundAt present, dementia has no known cure. Interventions to delay onset and reduce prevalence of the disease are therefore focused on risk factor reduction. Previous population attributable risk estimates for western countries may have been underestimated as a result of the relatively low rates of midlife obesity and the lower weighting given to that variable in statistical models.MethodsLevin’s Attributable Risk which assumes independence of risk factors was used to calculate the proportion of dementia attributable to seven modifiable risk factors (midlife obesity, physical inactivity, smoking, low educational attainment, diabetes mellitus, midlife hypertension and depression) in Australia. Using a recently published modified formula and survey data from the Australia Diabetes, Obesity and Lifestyle Study, a more realistic population attributable risk estimate which accounts for non-independence of risk factors was calculated. Finally, the effect of a 5–20% reduction in each risk factor per decade on future dementia prevalence was computed.ResultsTaking into consideration that risk factors do not operate independently, a more conservative estimate of 48.4% of dementia cases (117,294 of 242,500 cases) was found to be attributable to the seven modifiable lifestyle factors under study. We calculated that if each risk factor was to be reduced by 5%, 10%, 15% and 20% per decade, dementia prevalence would be reduced by between 1.6 and 7.2% in 2020, 3.3–14.9% in 2030, 4.9–22.8% in 2040 and 6.6–30.7% in 2050.ConclusionOur largely theory-based findings suggest a strong case for greater investment in risk factor reduction programmes that target modifiable lifestyle factors, particularly increased engagement in physical activity. However, further data on risk factor treatment and dementia risk reduction from population-based studies are needed to investigate whether our estimates of potential dementia prevention are indeed realistic.Electronic supplementary materialThe online version of this article (doi:10.1186/s13195-017-0238-x) contains supplementary material, which is available to authorized users.

ObjectiveTo examine the efficacy of body brain life (BBL), a 12-week online dementia risk reduction intervention.MethodsBBL was evaluated in a randomized controlled trial in 176 middle-aged adults with >2 risk factors and <2 protective factors for Alzheimer's disease (AD) assessed on a brief screening instrument. Participants were randomized to BBL, BBL plus face-to-face group sessions (BBL + FF) or active control (control). Score on the Australian National University-Alzheimer's disease risk index (ANU-ADRI), a validated index of AD risk, was the primary outcome measure assessed at baseline, 12, and 26 weeks.ResultsA group by time interaction at 26 weeks showed a significant reduction in ANU-ADRI score for BBL compared with control. Planned contrasts showed the BBL and BBL + FF groups had improvement in ANU-ADRI scores at 12 weeks (BBL + FF: z = −0.25; P = .021; BBL: z = −0.25; P = .008) and 26 weeks (BBL + FF: z = −0.48; P < .001; BBL: z = −0.28; P = .004) due to increase in protective factors.ConclusionsThis short intervention resulted in dementia risk reduction. Online dementia risk reduction interventions show promise for reducing the overall dementia risk in middle-aged adults with multiple risk factors.Clinical Trial Registration: The study is registered under Trial Registration: Reg. # ACTRN12612000147886.

Background The cross‐lagged panel (regression) model (CLPM) is the usual framework of choice to test the longitudinal reciprocal effects between self‐concept and achievement. Criticisms of the CLPM are that causal paths are over‐estimated as they fail to discriminate between‐ and within‐person variation. The random‐intercept cross‐lagged panel model (RI‐CLPM) is one alternative that extends the CLPM by partialling out between‐person variance. Aims We compare analyses from a CLPM and a RI‐CLPM which examine the reciprocal relationships between self‐concept, self‐efficacy, and achievement and determine the extent CLPM estimates are inflated by between‐person variance. Sample(s) Participants (n = 314) were first‐year undergraduate psychology students recruited as part of the STudent Engagement with Education and Learning (STEEL) project. Methods Participants completed measures of self‐efficacy and self‐concept prior to completing fortnightly quiz assessments. Results Cross‐Lagged Panel (regression) Model estimates are likely over‐estimated in comparison with RI‐CLPM estimates. Cross‐Lagged Panel (regression) Model analyses identified a reciprocal effects relationship between self‐concept and achievement, confirming established literature. In RI‐CLPM analyses, these effects were attenuated and a skill development association between achievement and self‐concept was supported. A reciprocal relationship between self‐efficacy and achievement was supported. Better model fit was reported for the RI‐CLPM analyses. Conclusions Prior findings relating to the reciprocal effects of self‐concept and achievement need to be reconsidered. Whilst such a relationship was supported in a CLPM analysis in this study, within an RI‐CLPM framework, only achievement predicted self‐concept. However, in both CLPM and RI‐CLPM models a reciprocal effects model of self‐efficacy and achievement was supported.